Light-emitting device

ABSTRACT

A light-emitting device includes a base member, a plurality of light sources on or above an upper surface of the base member, and a reflector that comprises a plurality of surrounding portions. Each of the plurality of surrounding portions surrounds a respective one of the plurality of light sources in a plan view. Each of the plurality of surrounding portions has inclined lateral surfaces widened upward. Intervals between adjacent ones of the plurality of light sources are constant in the plan view. Upper peripheries of the inclined lateral surfaces of each of the plurality of surrounding portions define an opening having a substantially rectangular shape. The plurality of surrounding portions include a plurality of first surrounding portions and a plurality of second surrounding portions surrounding the plurality of first surrounding portions. An area of the opening of each of the plurality of second surrounding portions is smaller than an area of the opening of each of the plurality of first surrounding portions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of copending application Ser. No.16/118,056, filed on Aug. 30, 2018, which claims priority under 35U.S.C. § 119(a) to Application No. 2017-167944, filed in Japan on Aug.31, 2017, and Application No. 2018-131915, filed in Japan on Jul. 11,2018, all of which are hereby expressly incorporated by reference intothe present application.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present disclosure relates to a light-emitting device.

2. Description of Related Art

Light-emitting devices each including a plurality of light sources havebeen proposed (see WO 2012/023459).

SUMMARY OF THE INVENTION

In a conventional light-emitting device, the luminance at an outerperipheral portion of the light-emitting device may be lower than theluminance at the central portion of the light-emitting device. This isbecause light emitted from other portions of the light emitting deviceeasily reach the central portion of the light-emitting device but doesnot easily reach the outer peripheral portion of the light-emittingdevice.

The present invention is made in view of the problem as described above.

According to one embodiment of the present invention, a light-emittingdevice includes a base member, a plurality of light sources on or abovean upper surface of the base member, and a reflector that comprises aplurality of surrounding portions. Each of the plurality of surroundingportions surrounds a respective one of the plurality of light sources ina plan view. Each of the plurality of surrounding portions has inclinedlateral surfaces widened upward. Intervals between adjacent ones of theplurality of light sources are constant in the plan view. Upperperipheries of the inclined lateral surfaces of each of the plurality ofsurrounding portions define an opening having a substantiallyrectangular shape. The plurality of surrounding portions include aplurality of first surrounding portions and a plurality of secondsurrounding portions surrounding the plurality of first surroundingportions. An area of the opening of each of the plurality of secondsurrounding portions is smaller than an area of the opening of each ofthe plurality of first surrounding portions.

In the light-emitting device as described above, the light density overthe surrounding portions at the outer peripheral portion of thelight-emitting device can be higher than the light density over thesurrounding portions at the central portion of the light-emittingdevice. Accordingly, a luminance similar to the luminance at the centralportion of the light-emitting device can be obtained at the outerperipheral portion of the light-emitting device, so that the luminanceover the light-emitting device can be closer to uniform throughout thedevice.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a schematic plan view of a light-emitting device according toa first embodiment.

FIG. 1B is a diagram in which a plurality of first surrounding portionsin FIG. 1A are shaded in gray.

FIG. 1C is a diagram in which a plurality of second surrounding portionsin FIG. 1A are shaded in gray.

FIG. 1D is a schematic cross-sectional view taken along the line 1D-1Din FIG. 1A.

FIG. 1E is a schematic, partial, enlarged view of FIG. 1D.

FIG. 1F is a schematic, partial, enlarged view of FIG. 1E.

FIG. 2A is a schematic cross-sectional view of another example of alight source in the first embodiment.

FIG. 2B is a schematic cross-sectional view of still another example ofa light source in the first embodiment.

FIG. 3 is a schematic cross-sectional view of another example of areflector in the first embodiment.

FIG. 4A is a diagram in which openings of an insulating member in afirst surrounding portion and a second surrounding portion in theschematic, partial, enlarged view of FIG. 1A are shaded in gray.

FIG. 4B is a schematic cross-sectional view of still another example ofa reflector in the first embodiment.

FIG. 5A is a schematic plan view of a light-emitting device according toa second embodiment.

FIG. 5B is a diagram in which the first surrounding portions in FIG. 5Aare indicated by portions shaded in gray.

FIG. 5C is a diagram in which the second surrounding portions in FIG. 5Aare shaded in gray.

FIG. 5D is a diagram in which a plurality of third surrounding portionsin FIG. 5A are shaded in gray.

FIG. 5E is a schematic cross-sectional view taken along the line 5E-5Ein FIG. 5A.

DETAILED DESCRIPTION OF EMBODIMENTS

Light-Emitting Device 1 According to First Embodiment

FIG. 1A is a schematic plan view of a light-emitting device according toa first embodiment. FIG. 1B is a diagram in which a plurality of firstsurrounding portions 32 in FIG. 1A are indicated by portions shaded ingray to facilitate the understanding of the locations of the firstsurrounding portions 32. FIG. 1C is a diagram in which a plurality ofsecond surrounding portions 34 in FIG. 1A are indicated by portionsshaded in gray to facilitate the understanding of the locations of thesecond surrounding portions 34. In FIG. 1A, FIG. 1B, and FIG. 1C, only abase member 10, light-emitting elements 22, and a reflector 30 areillustrated, and illustrations of other members such as an opticalmember 40 are omitted, to facilitate the understanding of the shape ofthe reflector 30. FIG. 1D is a schematic cross-sectional view takenalong the line 1D-1D in FIG. 1A. FIG. 1E is a schematic, partial,enlarged view of FIG. 1D. FIG. 1F is a schematic, partial, enlarged viewof FIG. 1E.

As shown in FIG. 1A to FIG. 1F, a light-emitting device 1 according tothe first embodiment includes the base member 10, a plurality of lightsources 20 on an upper surface of the base member 10, and the reflector30 that includes a plurality of surrounding portions each surrounding arespective one of the light sources 20 in a plan view, each of thesurrounding portions having inclined lateral surfaces X widened upward.The plurality of surrounding portions include the first surroundingportions 32 and the second surrounding portions 34 surrounding the firstsurrounding portions 32. Each of the second surrounding portions 34 hasan opening area, which is an area of a region defined by the upperperipheries of the inclined lateral surfaces X, smaller than an openingarea of each of the first surrounding portions 32. The details will bedescribed below.

Light-Emitting Device 1

The light-emitting device 1 is, for example, a direct-lit backlightdevice.

Base Member 10

The base member 10 is a member on or above which the light sources 20are mounted.

Examples of a material of the base member 10 include ceramics andresins, such as phenolic resins, epoxy resins, polyimide resins, BTresins, polyphthalamide (PPA), and poly(ethylene terephthalate) (PET).Examples of the ceramics include alumina, mullite, forsterite, glassceramics, and nitride (for example, AlN) and carbide (for example, SiC)ceramics, and LTCC. In the case where a resin is used as a material ofthe base member 10, glass fiber or an inorganic filler, such as SiO₂,TiO₂, or Al₂O₃, can be mixed into the resin to improve the mechanicalstrength, reduce the thermal expansion coefficient, and improve thelight reflectance. A metal substrate made in which an insulating layeris disposed on a surface of a metal member may be used for the basemember 10.

A thickness of the base member 10 can be selected appropriately. Thebase member 10 may be, for example, a flexible substrate that can bemanufactured using a roll-to-roll manner, or may be a rigid substrate.The rigid substrate may be a slim rigid substrate that is bendable.

Light Sources 20

The light sources 20 are disposed on or above the upper surface of thebase member 10.

The intervals between the light sources 20, in other words, intervals Pbetween adjacent light sources 20, is preferably uniform (including thecase where the intervals P are varied to the extent that is small enoughto be regarded as uniform) in the longitudinal and lateral directions ina plan view. With such intervals, the reflector 30 in which the size ofthe first surrounding portions 32 and the size of the second surroundingportions 34 are different from each other, for example, an opening areaS2 of each of the second surrounding portions 34 is smaller than anopening area S1 of each of the first surrounding portions 32, allows theluminance over the outer peripheral portion of the device to be the sameas the luminance over the central portion of the device without changingthe arrangement of the light sources 20. Thus, designing of thelight-emitting device 1 can be facilitated.

Each light source 20 may include the light-emitting element 22 such as alight-emitting diode. The light-emitting element 22 includes, forexample, a light-transmissive substrate and a semiconductor layerlayered on the substrate. For example, sapphire can be used for thelight-transmissive substrate. The semiconductor layer includes, forexample, an n-type semiconductor layer, an active layer, and a p-typesemiconductor layer in this order from a substrate side. For example,ZnSe, a nitride semiconductor (In_(x)Al_(y)Ga_(1−x−y)N, 0≤X, 0≤Y,X+Y≤1), GaP, GaAlAs, or AlInGaP, can be used for the semiconductorlayer. For example, an n-side electrode is formed on the n-typesemiconductor layer, and a p-side electrode is formed on the p-typesemiconductor layer.

Each light source 20 may include a sealing member 26. The sealing member26 protects the light-emitting element 22 against external environmentsand optically controls light that is output from the light-emittingelement 22. The sealing member 26 is disposed on or above the basemember 10 to cover the light-emitting element 22.

Examples of the material for the sealing member 26 include an epoxyresin, a silicone resin, a mixture of these resins, andlight-transmissive materials such as glass. Among these materials, asilicone resin is preferably selected in consideration of lightresistance and ease of molding. The sealing member 26 can contain alight-diffusing agent, a wavelength conversion member, such as aphosphor, that is adapted to absorb light emitted from thelight-emitting element 22 and emit light with a wavelength differentfrom the wavelength of light emitted from the light-emitting element 22,and a coloring agent corresponding to the emission color of thelight-emitting element 22.

The sealing member 26 can be formed by, for example, molding such ascompression molding or injection molding, dropping, or drawing.Alternatively, by optimizing the viscosity of a material of the sealingmember 26, the shape of the sealing member 26 can be controlled due tosurface tension of the material of the sealing member 26. In the case offorming the sealing member 26 by dropping or drawing, the sealing member26 can be formed in a simpler manner without using molds. Adjustment ofthe viscosity may be achieved by employing a material having a desiredviscosity as a material of the sealing member 26, or by using thelight-diffusing material as described above, wavelength conversionmember, or coloring agent.

Each light source 20 preferably has a batwing light distributioncharacteristic. In such a light distribution characteristic, the amountof light emitted directly upward from each light source 20 can bereduced, and a broad light distribution of the light source 20 can beachieved. Accordingly, the thickness of the light-emitting device 1 canbe reduced, particularly in the case where the light-transmissiveoptical member 40 is disposed to face the base member 10. Thus, alight-emitting device with a small thickness can be provided whilehaving a luminance over the outer peripheral portion of thelight-emitting device that is the same with the luminance over thecentral portion of the light-emitting device.

As used herein, the expression “batwing light distributioncharacteristic” refers to a light distribution characteristic in whichthe luminance at the central portion is smaller than the luminance atthe outer peripheral portion. Examples of the batwing light distributioncharacteristic include, with an optical axis L being 0°, a lightdistribution characteristic having an emission intensity distribution inwhich the emission intensity at angles with absolute values larger than0° is increased and a light distribution characteristic having anemission intensity distribution in which the emission intensity is thehighest at approximately in a range of 45° to 90°.

Each light source 20 may include a reflective layer 28 on the uppersurface of the light-emitting element 22. In this case, the sealingmember 26 can cover, for example, the light-emitting element 22 and areflective layer 28. With the sealing member 26 disposed in this manner,forming the sealing member 26 into a shape such as a shape describedbelow shown in FIG. 2A allows for easily achieving the batwing lightdistribution characteristic.

FIG. 2A is a schematic cross-sectional view of another example of thelight source in the first embodiment. The sealing member 26 may have,for example, a domical shape or, as shown in FIG. 2A, a shape thatallows for broadening the distribution of light emitted from thelight-emitting element 22, more specifically, a shape having a depressedportion directly above the light-emitting element. With this structure,the sealing member 26 functions as a lens to broaden the lightdistribution, and the batwing light distribution characteristic can beobtained without the reflective layer 28 as described above.Alternatively, the combination of the reflective layer 28 and thesealing member 26 that functions as a lens allows for obtaining thebatwing light distribution characteristic more easily.

FIG. 2B is a schematic cross-sectional view of still another example ofthe light source in the first embodiment. Each light source 20 mayinclude a reflective layer 28 over a sealing member 26 as shown in FIG.2B. With this structure, the reflective layer 28 reflects light emittedupward from the light-emitting element 22, so that the amount of lightemitted directly upward from the light-emitting element 22 can bereduced. Accordingly, the batwing light distribution characteristic iseasily achieved.

The reflective layer 28 may be a metal film or a dielectric multilayerfilm.

It is preferable that the light sources 20 can be driven separately fromone another, and in particular, light control (such as local dimming andhigh dynamic range: HDR) can be performed with respect to each of thelight sources 20.

Reflector 30

The reflector 30 reflects light emitted from the light sources 20. Thereflector 30 preferably has an average reflectance of 70% or more oflight emitted from the light sources 20 in a wavelength range of 440 nmto 630 nm. For example, a resin member containing a reflective materialmade of particles of a metal oxide such as titanium oxide, aluminumoxide, or silicon oxide, or a member in which a reflective member isdisposed on a surface of a resin member containing no reflectivematerial can be used for the reflector 30.

The reflector 30 includes a plurality of surrounding portions, each ofwhich surrounding a respective one of the plurality of light sources 20in a plan view. A single surrounding portion surrounds a single lightsource. The plurality of surrounding portions include the firstsurrounding portions 32 and the second surrounding portions 34surrounding the first surrounding portions 32. The opening area S2 ofeach of the second surrounding portions 34 is smaller than the openingarea S1 of each of the first surrounding portions 32. This structureallows the light density over the second surrounding portions 34 to behigher than the light density over the first surrounding portions 32,and thus allows the light density at the outer peripheral portion of thelight-emitting device to be higher than the light density at the centralportion of the light-emitting device. The “opening area” as used hereinrefers to an area of a region defined by the upper peripheries of theinclined lateral surfaces X. Further, the “light density” refers to thedegree of intensity of light per unit area.

The reflector 30 has openings of a substantially rectangular shape, eachof which is defined by upper peripheries of the inclined lateralsurfaces of the reflector 30. With the plurality of surrounding portioneach having the opening of a substantially rectangular shape, luminanceover the light-emitting device can be closer to uniform throughout thelight-emitting device.

The reflector 30 has a thickness T in a range of, for example, 100 μm to300 μm. Each of the plurality of surrounding portions of the reflector30 has inclined lateral surfaces X widened upward. The plurality ofsurrounding portions of the reflector 30 each preferably have a planarportion extending from the lower ends of the inclined lateral surfaces Xtoward the light source 20. In FIG. 1E, an inclination angle of each ofthe inclined lateral surfaces X of the second surrounding portion 34 islarger than an inclination angle of each of the inclined lateralsurfaces X of the first surrounding portion 32.

A distance D2 between an end portion of the planar portion of the secondsurrounding portion 34 at a light source 20 side and an end portion ofits corresponding light source 20 is preferably smaller than a distanceD1 between an end portion of the planar portion of the first surroundingportion 32 at the light source 20 side and an end portion of itscorresponding light source 20 as shown in, for example, FIG. 4B. Thisstructure allows the light density over the second surrounding portions34 to be higher than the light density over the first surroundingportions 32, so that the light density over the surrounding portions atthe outer peripheral portion of the light-emitting device higher thanthe light density over the surrounding portions at the central portionof the light-emitting device.

FIG. 3 is a schematic cross-sectional view of another example of areflector in the first embodiment. A height H2 between the upper surfaceof the base member 10 and an upper periphery of each of the inclinedlateral surfaces X of the second surrounding portions 34 is preferablygreater than a height H1 between the upper surface of the base member 10and an upper periphery of each of the first surrounding portions 32 asshown in FIG. 3. This structure allows for increasing the amount oflight that is multiple-reflected within the second surrounding portions34, which allows for further increasing light density over the secondsurrounding portions 34, so that the luminance over the outer peripheralportion of the light-emitting device can be increased.

Optical Member 40

The optical member 40 faces the base member 10 across a plurality oflight sources 20. A distance K2 between an upper periphery of each ofthe inclined lateral surfaces X and the optical member 40 is preferablyequal to or less than a half of a distance K1 between the upper surfaceof the base member 10 and an upper periphery of each of the inclinedlateral surfaces X. This structure allows a depth of each of the firstsurrounding portions 32 and a depth of each of the second surroundingportions 34 to be relatively greater than the distance between thereflector 30 and the optical member 40, so that the number ofrepetitions of multiple reflection of light within the first surroundingportions 32 and the second surrounding portions 34 can be increased.Accordingly, the light density of light from each surrounding portion atthe optical member 40 can be enhanced.

For example, a light-transmissive member such as a half mirror can beused for the optical member 40. For the half mirror, for example, amaterial that reflects a part of incident light and transmits the otherpart of the light can be used.

The half mirror preferably has a reflectance with respect to a lightincident in an oblique direction lower than a reflectance thereof withrespect to a light incident in a perpendicular direction. That is, thehalf mirror preferably has a property in which a reflectance of the halfmirror with respect to a light emitted from each light source 20 andemitted parallel to the optical axis direction is high and a lightreflectance decreases in accordance with increase in the radiation angle(in other words, the property in which the amount of light transmittedthrough the half mirror increases). As used herein, the light parallelto the optical axis direction is regarded to have a radiation angle of0°. This structure easily allows for providing a uniform luminancedistribution when the half mirror is observed from the emission surface.

For example, a dielectric multilayer film can be used for the halfmirror. With the use of a dielectric multilayer film, a reflective filmwith low light absorption can be obtained. Further, the reflectance canbe adjusted by changing the design of the film as desired, and thereflectance with respect to angle of emitted light can be controlled.For example, with the dielectric multilayer film designed to have areflectance with respect to a light incident in an oblique directionwith respect to the half mirror lower than a reflectance thereof withrespect to a light incident perpendicularly on the half mirror, aproperty can be easily realized in which a reflectance with respect tolight incident perpendicularly on the light-extracting surface is higherand a reflectance decreases in accordance with increase in the angle ofan incident light with respect to the light-extracting surface.

The light-emitting device 1 may include a light diffusing plate at anemission surface side of the optical member 40. The light diffusingplate diffuses light emitted from a plurality of light sources 20 toreduce unevenness in luminance. For the light diffusing plate, amaterial that absorbs little visible light, such as a polycarbonateresin, a polystyrene resin, an acrylic resin, or a polyethylene resincan be used. For example, a member that contains a base material and amaterial having a refractive index different from the refractive indexof the base material, or a member made of a base material and having asurface that is processed so as to scatter light can be used for thelight diffusing plate.

Conductor Wiring 50

Conductor wiring 50 for supplying electricity to the light sources 20(i.e., light-emitting elements 22) can be disposed on a surface of thebase member 10. The conductor wiring 50 is electrically connected toelectrodes of the light sources 20 (i.e., light-emitting elements 22)and is configured to supply a current (i.e., electricity) from outside.

A material of the conductor wiring 50 can be appropriately selected inaccordance with a material used for the base member 10 and a method ofmanufacturing the base member 10. For example, in the case where aceramic is used as a material of the base member 10, a material of theconductor wiring 50 is preferably a material having a melting point thatis high enough to endure sintering temperatures of a ceramic sheet. Ametal with a high melting point, such as tungsten and molybdenum, ispreferably used as a material of the base member 10. In addition, amember in which a surface of a metal member made of such a metal iscovered with another metal material, such as nickel, gold, and silver,by plating, sputtering, vacuum evaporation, or the like can be used asthe conductor wiring 50. In the case where a glass epoxy resin is usedas a material of the base member 10, a material that is easy to processis preferably used as a material of the conductor wiring 50.

The conductor wiring 50 can be formed on one or both of oppositesurfaces of the base member 10 by using a method such as vapordeposition, sputtering, or plating. Metal foil attached to the basemember 10 by pressing may serve as the conductor wiring 50. Theconductor wiring 50 can be patterned to have a predetermined shape byforming a mask on the conductor wiring 50 by printing orphotolithography and then performing etching using the mask.

Bonding Members 60

The light-emitting device 1 may include bonding members 60. The bondingmembers 60 fix the light sources 20 to the base member 10 and/or theconductor wiring 50. Examples of the bonding members 60 includeinsulating resins and electrically-conductive members. In the case wherethe light sources 20 are flip-chip mounted, electrically-conductivemembers can be used for the bonding members 60. Examples of the bondingmembers 60 include Au-containing alloys, Ag-containing alloys,Pd-containing alloys, In-containing alloys, Pb—Pd-containing alloys,Au—Ga-containing alloys, Au—Sn-containing alloys, Sn-containing alloys,Sn—Cu-containing alloys, Sn—Cu—Ag-containing alloys, Au—Ge-containingalloys, Au—Si-containing alloys, Al-containing alloys, Cu—In-containingalloys, and mixtures of metals and fluxes.

For example, a member in a form of liquid, paste, or solid(sheet-shaped, block-shaped, powdered, or wire-shaped) may be usedsingly or in combination for the bonding members 60. Appropriatematerials can be selected for the bonding members 60 in accordance withthe shape of the base member 10 and the composition. In the case whereelectrically connecting the light sources 20 to the conductor wiring 50and mounting or fixing the light sources 20 on or above the base member10 are not performed at once but are performed separately, wires otherthan the bonding members 60 can be used to electrically connect thelight sources to the conductor wiring 50.

Insulating Member 70

An insulating member 70 such as a resist may be disposed above the basemember 10 to insulate and cover the conductor wiring 50. With theinsulating member 70, the conductor wiring 50 can be insulated. Also,the insulating member 70 containing a white filler can reflect light andcan reduce leakage and absorption of light, so that light extractionefficiency of the light-emitting device 1 can be increased. For theinsulating member 70, any appropriate insulating material can beincreased, and a material that absorbs little light emitted from thelight-emitting elements 22 is particularly preferable. Specific examplesof the material used for the insulating member 70 include an epoxyresin, a silicone resin, a modified silicone resin, a urethane resin, anoxetane resin, an acrylic resin, a polycarbonate resin, and a polyimideresin.

The insulating member 70 preferably covers a surface of the base member10 and a portion of the conductor wiring 50 not electrically connectedto the light-emitting elements 22 or other components. The regions ofthe surface of the base member 10 above which the light-emittingelements 22 are disposed are preferably not covered with the insulatingmember 70, and an area S4 of an opening of the insulating member 70 ateach of the second surrounding portions 34 is preferably smaller than anarea S3 of an opening of the insulating member 70 at each of the firstsurrounding portions 32 as shown in FIG. 4A and FIG. 4B. This structureallows for further facilitating obtaining a luminance at the outerperipheral portion of the light-emitting device similar to the luminanceat the central portion of the device.

As described above, in the light-emitting device 1 according to thefirst embodiment, the light density over the surrounding portions in theouter peripheral portion of the light-emitting device is higher than thelight density over the surrounding portions in the central portion ofthe light-emitting device. Accordingly, a luminance over the outerperipheral portion of the light-emitting device can be similar to aluminance over the central portion of the light-emitting device, so thatthe luminance over the light-emitting device can be more uniformthroughout the device.

Light-Emitting Device 2 According to Second Embodiment

FIG. 5A is a schematic plan view of a light-emitting device according toa second embodiment.

FIG. 5B is a diagram in which the first surrounding portions 32 in FIG.5A are shaded in gray to facilitate the understanding of the locationsof the first surrounding portions 32. FIG. 5C is a diagram in which thesecond surrounding portions 34 in FIG. 5A are shaded in gray tofacilitate the understanding of the locations of the second surroundingportions 34. FIG. 5D is a diagram in which a plurality of thirdsurrounding portions 36 in FIG. 5A are shaded in gray to facilitate theunderstanding of the locations of the third surrounding portions 36.FIG. 5E is a schematic cross-sectional view taken along the line 5E-5Ein FIG. 5A.

As shown in FIG. 5A to FIG. 5E, a light-emitting device 2 according tothe second embodiment differs from the light-emitting device 1 accordingto the first embodiment in that the plurality of surrounding portionsfurther include the third surrounding portions 36 between the firstsurrounding portions 32 and the second surrounding portions 34, and thatthe opening area S3, which is an area of a region defined by the upperperipheries of the inclined lateral surfaces X of each of the thirdsurrounding portions 36, is smaller than the opening area S1 of each ofthe first surrounding portions 32 and larger than the opening area S2 ofeach of the second surrounding portions 34. Other configurations of thelight-emitting device 2 is the same as those of the light-emittingdevice 1. In the light-emitting device 2 according to the secondembodiment, the relationship of the light density over the secondsurrounding portions 34>the light density over the third surroundingportions 36>the light density over the first surrounding portions 32 issatisfied, and the light density over the light-emitting device isgradually increased from the central portion toward the outer peripheralportion of the device. Accordingly, a luminance over the outerperipheral portion of the device similar to the luminance over thecentral portion of the device can be obtained, so that the luminanceover the device can be even more uniform throughout the light-emittingdevice.

Certain embodiments of the present invention have been described above,but descriptions thereof do not limit the scope of the presentinvention.

What is claimed is:
 1. A light-emitting device comprising: a basemember; a plurality of light sources arranged on or above an uppersurface of the base member at intervals in a lateral direction and alongitudinal direction; and a reflector that comprises a plurality ofsurrounding portions, each of the plurality of surrounding portionssurrounding a respective one of the plurality of light sources in a planview, each of the plurality of surrounding portions having four inclinedlateral surfaces widened upward, wherein intervals between adjacent onesof the plurality of light sources in both the lateral and longitudinaldirections are substantially constant in the plan view, wherein upperperipheries of the inclined lateral surfaces of each of the plurality ofsurrounding portions define an opening having, in the plan view, asubstantially rectangular shape with four substantially straight sides,wherein the plurality of surrounding portions include a plurality offirst surrounding portions and a plurality of second surroundingportions surrounding the plurality of first surrounding portions,wherein an area of the opening of each of the plurality of secondsurrounding portions is smaller than an area of the opening of each ofthe plurality of first surrounding portions.
 2. The light-emittingdevice according to claim 1, wherein the plurality of surroundingportions further include a plurality of third surrounding portions,wherein the third surrounding portions are disposed between the firstsurrounding portions and the second surrounding portions, and wherein anarea of the opening of each of the plurality of the third surroundingportions is smaller than the area of the opening of each of the firstsurrounding portions and larger than the area of the opening of each ofthe second surrounding portions in the opening area.
 3. Thelight-emitting device according to claim 2, wherein each of the lightsources has a batwing light distribution characteristic.
 4. Thelight-emitting device according to claim 3, wherein each of the lightsources comprises: a light-emitting element, and a lens adapted tobroaden a distribution of light emitted from the light-emitting element.5. The light-emitting device according to claim 2, wherein each of thelight sources comprises: a light-emitting element, and a lens adapted tobroaden a distribution of light emitted from the light-emitting element.6. The light-emitting device according to claim 2, further comprising alight-transmissive optical member facing the base member across theplurality of light sources, wherein a distance between the upperperiphery of each of the inclined lateral surfaces and the opticalmember is equal to or less than a half of a distance between the uppersurface of the base member and the upper periphery of the inclinedlateral surface.
 7. The light-emitting device according to claim 1,wherein each of the light sources has a batwing light distributioncharacteristic.
 8. The light-emitting device according to claim 7,wherein each of the light sources comprises: a light-emitting element,and a lens adapted to broaden a distribution of light emitted from thelight-emitting element.
 9. The light-emitting device according to claim8, further comprising a light-transmissive optical member facing thebase member across the plurality of light sources, wherein a distancebetween the upper periphery of each of the inclined lateral surfaces andthe optical member is equal to or less than a half of a distance betweenthe upper surface of the base member and the upper periphery of theinclined lateral surface.
 10. The light-emitting device according toclaim 3, further comprising a light-transmissive optical member facingthe base member across the plurality of light sources, wherein adistance between the upper periphery of each of the inclined lateralsurfaces and the optical member is equal to or less than a half of adistance between the upper surface of the base member and the upperperiphery of the inclined lateral surface.
 11. The light-emitting deviceaccording to claim 1, wherein each of the light sources comprises: alight-emitting element, and a lens adapted to broaden a distribution oflight emitted from the light-emitting element.
 12. The light-emittingdevice according to claim 11, further comprising a light-transmissiveoptical member facing the base member across the plurality of lightsources, wherein a distance between the upper periphery of each of theinclined lateral surfaces and the optical member is equal to or lessthan a half of a distance between the upper surface of the base memberand the upper periphery of the inclined lateral surface.
 13. Thelight-emitting device according to claim 1, wherein each of the lightsources comprises: a light-emitting element, a sealing member coveringthe light-emitting element, and a reflective layer above the sealingmember.
 14. The light-emitting device according to claim 1, wherein eachof the light sources comprises: a light-emitting element having an uppersurface, a reflective layer on the upper surface of the light-emittingelement, and a sealing member covering the light-emitting element andthe reflective layer.
 15. The light-emitting device according to claim14, further comprising a light-transmissive optical member facing thebase member across the plurality of light sources, wherein a distancebetween the upper periphery of each of the inclined lateral surfaces andthe optical member is equal to or less than a half of a distance betweenthe upper surface of the base member and the upper periphery of theinclined lateral surface.
 16. The light-emitting device according toclaim 1, further comprising a light-transmissive optical member facingthe base member across the plurality of light sources, wherein adistance between the upper periphery of each of the inclined lateralsurfaces and the optical member is equal to or less than a half of adistance between the upper surface of the base member and the upperperiphery of the inclined lateral surface.
 17. The light-emitting deviceaccording to claim 16, wherein the optical member comprises a halfmirror made of a dielectric multilayer film, the half mirror adapted toreflect a part of incident light and to transmit the other part of thelight.
 18. The light-emitting device according to claim 1, wherein thereflector includes planar portions each extending from a lower end ofeach of the inclined lateral surfaces toward a corresponding one of theplurality of light sources, and wherein a distance between an endportion of the planar portion of each of the second surrounding portionsat a light source side and an end portion of a corresponding one of thelight sources is smaller than a distance between an end portion of theplanar portion of each of the first surrounding portions at the lightsource side and an end portion of a corresponding one of the lightsources.
 19. The light-emitting device according to claim 1, wherein aheight between the upper surface of the base member and the upperperiphery of the inclined lateral surface of each of the secondsurrounding portions is greater than a height between the upper surfaceof the base member and an upper periphery of each of the firstsurrounding portions.
 20. The light-emitting device according to claim1, the light-emitting device further comprising: conductor wiringselectrically connected to corresponding ones of the light sources on asurface of the base member; and an insulating member covering a portionof each of the conductor wirings not electrically connected to the lightsources.
 21. The light-emitting device according to claim 1, wherein,for each of the plurality of second surrounding portions, at least oneof the four inclined lateral surfaces has an equivalent area in planview as each of the inclined lateral surfaces of the plurality of firstsurrounding portions, the at least one of the four inclined lateralsurfaces not being closer to an outer edge of the base member than theothers of the four inclined surfaces.
 22. The light-emitting deviceaccording to claim 21, wherein the base member is substantiallyrectangular, and for at least one of the second surrounding portionslocated at a corner of the base member in plan view, the at least one ofthe four inclined lateral surfaces is comprised of the two inclinedlateral surfaces located not closest to respective sides of the basemember.